from psycopg2 import pool

from db_config import db_config

config = db_config()
connection_params = config['postgresql']

pool = pool.SimpleConnectionPool(int(config['pool']['min']), 
                                      int(config['pool']['max']), 
                                      **connection_params)

CUSTOMER_ID_SQL = ''' select c.customer_pk from fo_customer c 
where c.login = %s;
'''

user_login = 'root'

connection = pool.getconn()
cursor = connection.cursor()
cursor.execute(CUSTOMER_ID_SQL, (user_login, ))
result = cursor.fetchall()
print(result)